Research On In-Band RCS Reduction Of X-Band Vivaldi Array Antenna

In modern warfare,the stealth capabilities of airborne and shipborne weaponry platforms in radar detection are becoming increasingly important.With the widespread application of Phased Array Radar,the array antenna in phased array radar has become the main contributor to the Radar Cross Section(RCS)of the entire stealth platform,and the antenna is more complicated than ordinary objects.The in-band stealth design of the scattering characteristics is very difficult,so it is of great significance to perform the scattering analysis and stealth design of the array antenna.Vivaldi antennas are widely used in modern Phased Array Radars due to their ease of processing,mechanical reliability,operating frequency bandwidth,and ease of integration with other firmware.In this paper,the Vivaldi array antenna,a typical antenna for X-band radar,is used to conduct in-band stealth research.The thesis work includes the following:(1)Introduce the background and significance of antenna stealth research,summarize the domestic and international research status of antenna stealth technology,and give the content of the paper.(2)First introduced the Vivaldi antenna similarity principle and antenna scattering theory,then gave two calculation methods of the antenna RCS open circuit short circuit method and radiation method,and finally introduced the phased array antenna RCS theory,and gave the phase control Array antenna mode item RCS estimation formula.(3)An X-band Vivaldi antenna unit was designed and optimized to form a 3×3 antenna array to study its radiation performance,and the antenna RCS was calculated using the formula in Chapter 2.(4)Introduce the characteristic mode theory,analyze the characteristic mode of the Vivaldi antenna structure,and design a surface current suppression structure based on the simulation of the antenna characteristic mode composition and surface current distribution,and realize the in-band RCS reduction of the Vivaldi antenna.At the same time,the radiation characteristics of the antenna are optimized.(5)The influence of the parabolic reflector on the radiation and scattering characteristics of the antenna array is studied.Through phase calculation,an artificial magnetic conductor structure is designed to fit the equivalent parabolic reflector,which is effectively reduced on the basis of not affecting the antenna radiation performance.In-band RCS of the array antenna.